Yan Kai, deputy director of the China Ship Scientific Research Center affiliated with the China Shipbuilding Industry Corp, said infrastructure in the South China Sea must improve in order to safeguard the nation's interests.

Yan also singled out the importance of establishing an airport in light of this weekend's disappearance of a Malaysian Airlines Boeing 777.

"We do not have major ports and airports in the Nansha Islands and we could not immediately set off to search for the aircraft. You can see how urgent it is to have a port and airport in the South China Sea," said Yan, who was one of the key engineers who manned China's deep-sea submersible Jiaolong.

China's Nansha Islands are located in the South China Sea and said to have vast oil and natural gas reserves. He said "backward infrastructure has limited development".

Yan, who is also a deputy to the National People's Congress, made his remarks during the ongoing annual session.

He pointed out that limited infrastructure has made it "extremely difficult" for people to live and work in the South China Sea area, especially for oil and gas companies and for fishermen and maritime law enforcement.

There is only one military airport that is crudely constructed and one port in the Yongxing Island, which is the largest island in the South China Sea at 2 million square km and administered by Sansha, Hainan province, Yan said. He added that there is no infrastructure in the Nansha Islands, which are more than 1,000 km from the mainland.

Sansha, China's youngest and southernmost city in Hainan province, was established in 2012 to govern more than 200 small islands, sand banks and reefs in the Xisha, Zhongsha and Nansha islands. Yongxing Island, which is part of the Xisha Islands, has about 1,000 residents and a military garrison.

One month after the city's establishment, it launched its first infrastructure projects with sewage disposal and waste collection facilities on Yongxing Island. Sansha's municipal officials have since made efforts to construct harbors, airports and docks as well as other infrastructure. The city's investment into the island stood at more than 10 billion yuan ($1.6 billion) at that time.

Yan urged a step-by-step process in building the South China Sea, with basic living infrastructure to ensure there is support for law enforcement, tourism and oil and gas development in the South China Sea. City officials should then build airports and seaports, he said.

"This move could provide places for docking, runways for aircraft and facilities for the supply of oil, power, drinkable water and medical care," he said.

But Li Guoqiang, deputy director of the Center for Chinese Borderland History and Geography at the Chinese Academy of Social Sciences, said even if such infrastructure is built, it should be built on the larger Hainan provincial island and not on the more remote islands.

"The ecological environment in the region is so vulnerable that we cannot sacrifice it for economic interests," he said.

zhaoshengnan@chinadaily.com.cn